<p>daniel has uploaded this change for <strong>review</strong>.</p><p><a href="https://gerrit.osmocom.org/c/libosmocore/+/23167">View Change</a></p><pre style="font-family: monospace,monospace; white-space: pre-wrap;">stats: Ensure that each osmo_stat_item only reports once per interval<br><br>We should never report multiple values for a metric. It is confusing for<br>the log reporter and wrong for statsd. Statsd will record only one value,<br>but will it be the first, last, ...?<br>This can happen if an osmo_stat_item changes more than once within the<br>same reporting interval.<br><br>With this patch only one aggregate value is sent to the log reporters.<br>The value reported is the maximum during this interval. Other<br>aggregations could be possible (min, last), but reporting a (useful)<br>average is not because the values don't include a timestamp and most<br>osmo_stat_items change at unregular intervals.<br><br>Change-Id: I366ab1c66f4ae6363111ea4e41b66b7d5bcade9c<br>Related: SYS#4877<br>---<br>M src/stats.c<br>M tests/stats/stats_test.c<br>M tests/stats/stats_test.ok<br>3 files changed, 43 insertions(+), 18 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;">git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/67/23167/1</pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/src/stats.c b/src/stats.c</span><br><span>index a0834d2..6af77f9 100644</span><br><span>--- a/src/stats.c</span><br><span>+++ b/src/stats.c</span><br><span>@@ -699,31 +699,36 @@</span><br><span> int have_value;</span><br><span> </span><br><span> have_value = osmo_stat_item_get_next(item, &idx, &value) > 0;</span><br><span style="color: hsl(0, 100%, 40%);">- if (!have_value)</span><br><span style="color: hsl(120, 100%, 40%);">+ if (!have_value) {</span><br><span> /* Send the last value in case a flush is requested */</span><br><span> value = osmo_stat_item_get_last(item);</span><br><span style="color: hsl(120, 100%, 40%);">+ } else {</span><br><span style="color: hsl(120, 100%, 40%);">+ int32_t next_val;</span><br><span style="color: hsl(120, 100%, 40%);">+ int got_next = 0;</span><br><span style="color: hsl(120, 100%, 40%);">+ // If we have multiple values only send the max</span><br><span style="color: hsl(120, 100%, 40%);">+ do {</span><br><span style="color: hsl(120, 100%, 40%);">+ got_next = osmo_stat_item_get_next(item, &idx, &next_val) > 0;</span><br><span style="color: hsl(120, 100%, 40%);">+ if (got_next) {</span><br><span style="color: hsl(120, 100%, 40%);">+ value = OSMO_MAX(value, next_val);</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+ } while (got_next);</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- do {</span><br><span style="color: hsl(0, 100%, 40%);">- llist_for_each_entry(srep, &osmo_stats_reporter_list, list) {</span><br><span style="color: hsl(0, 100%, 40%);">- if (!srep->running)</span><br><span style="color: hsl(0, 100%, 40%);">- continue;</span><br><span style="color: hsl(120, 100%, 40%);">+ llist_for_each_entry(srep, &osmo_stats_reporter_list, list) {</span><br><span style="color: hsl(120, 100%, 40%);">+ if (!srep->running)</span><br><span style="color: hsl(120, 100%, 40%);">+ continue;</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- if (!have_value && !srep->force_single_flush)</span><br><span style="color: hsl(0, 100%, 40%);">- continue;</span><br><span style="color: hsl(120, 100%, 40%);">+ if (!have_value && !srep->force_single_flush)</span><br><span style="color: hsl(120, 100%, 40%);">+ continue;</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- if (!osmo_stats_reporter_check_config(srep,</span><br><span style="color: hsl(0, 100%, 40%);">- statg->idx, statg->desc->class_id))</span><br><span style="color: hsl(0, 100%, 40%);">- continue;</span><br><span style="color: hsl(120, 100%, 40%);">+ if (!osmo_stats_reporter_check_config(srep,</span><br><span style="color: hsl(120, 100%, 40%);">+ statg->idx, statg->desc->class_id))</span><br><span style="color: hsl(120, 100%, 40%);">+ continue;</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- osmo_stats_reporter_send_item(srep, statg,</span><br><span style="color: hsl(0, 100%, 40%);">- item->desc, value);</span><br><span style="color: hsl(0, 100%, 40%);">- }</span><br><span style="color: hsl(120, 100%, 40%);">+ osmo_stats_reporter_send_item(srep, statg,</span><br><span style="color: hsl(120, 100%, 40%);">+ item->desc, value);</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- if (!have_value)</span><br><span style="color: hsl(0, 100%, 40%);">- break;</span><br><span style="color: hsl(0, 100%, 40%);">-</span><br><span style="color: hsl(0, 100%, 40%);">- have_value = osmo_stat_item_get_next(item, &idx, &value) > 0;</span><br><span style="color: hsl(0, 100%, 40%);">- } while (have_value);</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span> </span><br><span> return 0;</span><br><span> }</span><br><span>diff --git a/tests/stats/stats_test.c b/tests/stats/stats_test.c</span><br><span>index 71f710a..05caf98 100644</span><br><span>--- a/tests/stats/stats_test.c</span><br><span>+++ b/tests/stats/stats_test.c</span><br><span>@@ -440,6 +440,20 @@</span><br><span> osmo_stats_report();</span><br><span> OSMO_ASSERT(send_count == 2);</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+ printf("report (group 1, item 1 update twice):\n");</span><br><span style="color: hsl(120, 100%, 40%);">+ osmo_stat_item_set(statg1->items[TEST_A_ITEM], 10);</span><br><span style="color: hsl(120, 100%, 40%);">+ osmo_stat_item_set(statg1->items[TEST_A_ITEM], 10);</span><br><span style="color: hsl(120, 100%, 40%);">+ send_count = 0;</span><br><span style="color: hsl(120, 100%, 40%);">+ osmo_stats_report();</span><br><span style="color: hsl(120, 100%, 40%);">+ OSMO_ASSERT(send_count == 2);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ printf("report (group 1, item 1 update twice, check max):\n");</span><br><span style="color: hsl(120, 100%, 40%);">+ osmo_stat_item_set(statg1->items[TEST_A_ITEM], 20);</span><br><span style="color: hsl(120, 100%, 40%);">+ osmo_stat_item_set(statg1->items[TEST_A_ITEM], 10);</span><br><span style="color: hsl(120, 100%, 40%);">+ send_count = 0;</span><br><span style="color: hsl(120, 100%, 40%);">+ osmo_stats_report();</span><br><span style="color: hsl(120, 100%, 40%);">+ OSMO_ASSERT(send_count == 2);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> printf("report (remove statg1, ctrg1):\n");</span><br><span> /* force single flush */</span><br><span> srep1->force_single_flush = 1;</span><br><span>diff --git a/tests/stats/stats_test.ok b/tests/stats/stats_test.ok</span><br><span>index 8628adb..26d9e38 100644</span><br><span>--- a/tests/stats/stats_test.ok</span><br><span>+++ b/tests/stats/stats_test.ok</span><br><span>@@ -100,6 +100,12 @@</span><br><span> report (group 1, item 1 update):</span><br><span> test2: item p= g=test.one i=1 n=item.a v=10 u=ma</span><br><span> test1: item p= g=test.one i=1 n=item.a v=10 u=ma</span><br><span style="color: hsl(120, 100%, 40%);">+report (group 1, item 1 update twice):</span><br><span style="color: hsl(120, 100%, 40%);">+ test2: item p= g=test.one i=1 n=item.a v=10 u=ma</span><br><span style="color: hsl(120, 100%, 40%);">+ test1: item p= g=test.one i=1 n=item.a v=10 u=ma</span><br><span style="color: hsl(120, 100%, 40%);">+report (group 1, item 1 update twice, check max):</span><br><span style="color: hsl(120, 100%, 40%);">+ test2: item p= g=test.one i=1 n=item.a v=20 u=ma</span><br><span style="color: hsl(120, 100%, 40%);">+ test1: item p= g=test.one i=1 n=item.a v=20 u=ma</span><br><span> report (remove statg1, ctrg1):</span><br><span> test2: counter p= g=ctr-test:one_dot i=3 n=ctr:a v=0 d=0</span><br><span> test1: counter p= g=ctr-test:one_dot i=3 n=ctr:a v=0 d=0</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/c/libosmocore/+/23167">change 23167</a>. 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<div style="display:none"> Gerrit-Project: libosmocore </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-Change-Id: I366ab1c66f4ae6363111ea4e41b66b7d5bcade9c </div>
<div style="display:none"> Gerrit-Change-Number: 23167 </div>
<div style="display:none"> Gerrit-PatchSet: 1 </div>
<div style="display:none"> Gerrit-Owner: daniel <dwillmann@sysmocom.de> </div>
<div style="display:none"> Gerrit-MessageType: newchange </div>